title: DNA adducts and combinations of multiple lung cancer at-risk alleles in environmentally exposed and smoking subjects.
abstract: Interindividual variation in DNA adduct levels in individuals exposed to similar amounts of environmental carcinogens may be due to genetic variability. We analysed the influence of genes involved in determining/modifying DNA damage, including microsomal epoxide hydrolase1 (EPHX1) His139Arg, N-acetyl-transferase, NAD(P)H:quinone oxidoreductase1 (NQO1) Pro187Ser, manganese superoxide dismutase2 (MnSOD2) Val16Ala, and apurinic/apyrimidinic endonuclease1 (APE1) Asp148Glu polymorphisms in blood of 120 smokers. Subsequently, we examined the effects of the combinations of the variant alleles of EPHX, NQO1 and MnSOD2 together with the wild type allele of APE1 on DNA damage by calculating the "sum of at-risk alleles." We reviewed the studies examining the relationships of DNA adducts with at-risk alleles in environmentally exposed subjects. Our findings showed that smokers carrying the EPHX1-139Arg and the NQO1-187Ser variants were significantly more likely to have higher adduct levels. Null associations were found with the other variants. Nevertheless, DNA adduct levels in smokers with ≥5 at-risk alleles were significantly different from those with fewer than two alleles. A similar picture emerged from studies of DNA adducts and at-risk alleles in environmentally exposed and smoking subjects. Certain at-risk allele combinations may confer a greater likelihood of increased levels of adducts after environmental insults. The increase in DNA adduct levels in susceptible subjects exposed to environmental carcinogens may reflect changes in the mechanisms that protect cells from the accumulation of genetic damage. Alterations of the physiological processes designed to maintain homeostasis may reduce the individual "genotoxic tolerance" to environmental challenges and result in phenotypes characterized by high levels of DNA adducts.
authors.affiliation: Cancer Risk Factor Branch, Cancer Prevention and Research Institute, Florence, Italy. m.peluso@ispo.toscana.it
authors.forename: Marco E M
authors.initials: ME
authors.lastname: Peluso
authors.forename: Armelle
authors.initials: A
authors.lastname: Munnia
authors.forename: Petcharin
authors.initials: P
authors.lastname: Srivatanakul
authors.forename: Adisorn
authors.initials: A
authors.lastname: Jedpiyawongse
authors.forename: Suleeporn
authors.initials: S
authors.lastname: Sangrajrang
authors.forename: Marcello
authors.initials: M
authors.lastname: Ceppi
authors.forename: Roger W L
authors.initials: RW
authors.lastname: Godschalk
authors.forename: Frederik J
authors.initials: FJ
authors.lastname: van Schooten
authors.forename: Paolo
authors.initials: P
authors.lastname: Boffetta
mesh_terms: D018736:DNA Adducts; D004249:DNA Damage; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000235:genetics; D004781:Environmental Exposure; D004851:Epoxide Hydrolases / Q000235:genetics; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics*; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000235:genetics; D012306:Risk; D012907:Smoking; D013482:Superoxide Dismutase / Q000235:genetics; D014028:Tobacco Smoke Pollution; D000099156:Superoxide Dismutase 2
chemical_list: D018736:DNA Adducts; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D004851:Epoxide Hydrolases; D016660:NAD(P)H Dehydrogenase (Quinone); D013482:Superoxide Dismutase; D014028:Tobacco Smoke Pollution; D000099156:Superoxide Dismutase 2; C447479:NQO1 protein, human; C522330:EPHX1 protein, human; C085108:APEX1 protein, human
keywords: DNA adducts; environmental exposures; genetic susceptibility; multiple alleles